from zope import interface, schema

class IBookShelfIndexes(interface.Interface):
    title = schema.TextLine(title=u"Title", required=True)

class IBook(IBookShelfIndexes):
    creators = schema.Tuple(title=u"Authors",
                           required=False,
                           value_type=schema.TextLine(),
                           default=())

class IArticle(IBookShelfIndexes):
    issued = schema.Datetime(title=u"Issued", required=False)
